Brass-melting furnace



June; 30, 1925. 1,543,695

0. A. COLBY BRASS MELTING'F'URNACE Filed Jan. 12, 1923 WITNESSES:INVENTOR WW Ova A. Colby.

f Furnaces,

Patented June 30, 1925.

, unlrsn srsrss 1,543,695 A'rsn'r .QFFICE.

oaa A. COLBY, OF'IBWIH, rxnnsynvamn, assmnon TO wns'rmsnons'amacrrarc aMANUFACTURING comm, aoonromnon or .rznnsrnvanm Buss-maniac summon.

Application ileflianuary 12, 1923. Serlalh'c, 612,204.

To all lbkpm it may-;lconcem;; Be itkno'w'n that; I, (lanai, -Co1';1ir,' a Oil zen-'of -tlie"United States, an 'a-resident of Irwin, in thecounty of Viestm'oreland and Stateof' Pennsylvania, haveinvented a newand useful Improvement in Brass-Melting of'n hic-h the following is aspecification."'"

My invention relates to electric furnaces and" particularly to electric'resistance tur- I The object of my-inventionis to provide a relativelysimple, compact and symmetrical refractory heating element for anricet-ric'furnaoe;

In practicing my invention, I provide a plurality of radially extending,relatively thin, flat, refractory resistor plates located in spacedrelation in a SIXbStzilitlflll) circulaf'p'ath, with granularelectric-conducting material located.- thercbetween. Paus of oppositelybereled, refractory end blocks located in symmetrically spaces positions(hride the plates into group-r, .the number thereof bemgin accordancewith the number of'phascs of an alternating current supplycircuitfleleotrically connected thereto. Resilient means are provided topress a plurality of refractory terminal members min close operativeengagement with the pairs of beveledend blocks to maintain the platesand the granular material in close operative engagement.

The heating element may be located in a suitable electric-insulating andhcat'insulating casing adapted to the work to be dope in the furnace. Inthe single sheet of drawings, I Figi'ure 1 is a view, in verticalsection, of an electric furnace comprising the device embodying myinvention,

Fig. 2- is a view, in horizontal section thereof, talgen on the. linelL-II cf Fig. 1, and

3 and 4- are diagrammatic top plan views of heating elements arrangedfor energization from a two-phase and a three-phase supplycircuitrespectively.

An electric furnace 11 comprises an outer metallic casing 12 of anysuitable or desired contour end dimension, huthcrc shown assubstantially circular in contour. An outer layer 13 comprises either aplurality of bricks onblorks ora mass of a suitable heat-insulatingrefractory material. An

inner layer 14 comprises a lining of asuitable .ihigbvte-mperatureresisting refractory material.- A: third inner linin" andmuflle 15 maycomprise a relatively 61in layer of a refractory material which isparticular-l adapted to withstand the relatively high temperaturesencountered in the operation of the furnace;- The hereinbefore describedlayers oftefractory material define or sur rounda chamber 16 which, asit is; desi red to employ-a substantially circular crucible 17 therein,is also made substantially circular in horizontal contour. A covermember 18 of sheet metal may be provided to substan-. tially close thetop.of the chamber '16 to prevent heat loss therefrom or topreventobjects falling therein.

A heating element, which is supported on the floor of the furnace,comprises alurality of radially extending, relatively t in, flat.refractory, electric-conducting plates 19 which may consist-of graphite,carbon, or other similar material. The plates 19 are located in spacedrelation in a substantially circular path, their outer edges beinglocated close to, or operatively engaging, the inner surface of the.mufiie 15. Relatively small masses 21, of a granular electric conductingmaterial, such as comminuted carbon, "are located between the adjacentspaced plates, the mass extending to within a short distance of theouter edge of the plates. The plates 19 and the interposed mass ofgranular material are divided into a plurality of. synnnetrically spacedgroups by a plurality of pairs of oppositely beveled refractory endblocks 22 and 23 which are located in spaced relation in substantiallythe same path as are the plates 19. n

A plurality of refractory terminal mem- A, of wedge shape. are locatedbetween and operativcly engage the opposing beveled surfaces of thepairs of end blocks 22 and 23. the dimensions of the blocks 24 beingsuch that. the blocks are notlocated in the same horizontal plane as arethe plates 19, but extend thereabove in order that they may be moved ina direction at right angles to the plane of the circular path in whichthe plates 19 are located. to maintain them in close operativeengagement with the end blocks 22 and 2 to maintain these in closeoperative engagementwith the adjacent plates 19 and also to maintain theplates 19 and the masses 21 in close operative engage- 'jacent terminalsis,

ment with each other during the operation of the furnace.

Each of the members 24 is provided with an opening 25 extendingtherethrough and a water cooled, electric-circuit terminal member 26 ofa suitable material, such as copper. has its upper end located inandextending through the opening 25. A helical spring 27 surroumlsthe rod26 over a portion of its length, laterally extending flange portion 28being provided on the member 26 against which the outer end of thespring 27 may rest. The inner end of the spring 27 rests against aninsulating portion of the casing, suitable provision being. of course,necessary-to prevent current flowing through the furnace structure fromone of the terminal membersto the other. As this construction is no partof the present invention, I have not illustrated it in detail. Aninlet'conduit 29 and an outlet conduit 31 is provided with terminalmembers 26 to pern'htpf water cooling the same.

If it is desired phase alternating only one pair of refractory terminalblocks 24 and the (so-operating pairs of end blocks 22 and 23 will beprovided substantially as illustrated in Figs. 1 and 2 of the drawing.The current path is, in this case, from one of the terminal members 26and then through the two sets of plates and masses of granular materialin parallel-circuit relation, to the other and diametrically opposedterminal members. If it is desired to em loy a heating element of theabove descri d t pe, on a two-phase circuit, two pairs of books 24 arelocated 90" a art, substantially as illustrated in Fig. 3 o the drawing,and a current ath between adthere ore, only through one A of theperiphery of a circle. In case it is'desired to energize the heatingelement from a three-phase source of supply, the terminal members 24will be three in number and located 120 9. art, substantially asillustrated in Fig. 4 o the drawing.

If it is desired to employ a heating element of the hereinbeforedescribed type in a brass rmelting furnace, the construction is suchthat the. crucible 17 may be placed within the furnace chamber 16 andthe heat ing element is placed adjacent to the surrounding bottom of thecrucible. Suitable means, such as short shafts 32, may be secured to themetallic casing 12 in order that the entire furnace structure may betilted in a suitable mechanism (not shown) to permit of emptying thecrucible as desired.

While I have illustrated my improved heating element in a furnaceparticularly adapted to the melting of brass in a crucible, it is notlimited thereto and may be located to operate from a direct. currentsource of supply or from a single current source of supply in a suitablefurnace construction, which is adapted to the work to be performed in achamber constituted by refractory walls.

Various changes in ctail and arrangement may be made without departingfrom the spirit and scope of the invention and such modifications areintended to be covered by the appended claims.

I claim as my invention:

1. An electric resistance furnace comprising a plurality of radiallyextending, relatively thin, flat, refractory resistor )lates, located ina substantially circular pat 1, and a plurality of refractory terminalmembers, of wedge shape, interposed between certain of said plates andsymmetrically spaced circumferentially thereof.

2. An electric resistance furnace comprising a plurality of radiallyextending, relatively thin, flat, refractory resistor plates,

located in spaced relation in a substantially circular path,electric-conducting material connecting adjacent lates, airs ofoppositely' beveled space end b ocks divi mg said plates intosymmetrical groups, refractory terminal members, of wed e shape, locatedbetween said pairs of en blocks, and resilient means operativelyengaging said terminal members for forcing them laterally of said platesto compress the same.

4. An electric resistance furnace comprising a plurality of radiallyextending, relatively thin, flat, refractory resistor plates, locatedinspaced relation 1n a substantially circular path, granular refractoryelectricconducting material located between and connecting adjacentplates, and resiliently actuated means movable in a plane substantiallyparallel to the flat surfaces of said plates for compressing saidgranular electric-eonducting material between said plates and forconducting current to and from said plates and said granular material.

5. An electric resistance furnace com rising a substantially circularwall of re ractory electric-insulating material, a plurality of radiallyextendin relatively thin, flat carbonaceous plates coated in spacedrelation in a substantially circular path, granular electric-conductingmaterial located between and connecting adjacent plates, a plurality ofpairs of o positely beveled, spaced carbonaceous end b ocks dividingsaid plates and interposed granular material into sym- .terial isconnected,

ber of said groups being in accordance with the number of phases of asupply circuit to which said sets of plates and granular maandnefractory electriccircuit terminal members, of wedge shape 0 rativelyengaging-said respective pairs .0 beveled end blocks;

plates locatei stantially 6. In an electric resistancefurnace, incombination, a plurality of radially extending,relatively'thin, flat,refractory resistor in spaced relation m a subcircular path, granularelectriceonducting,material between said platcs,a

veled refractnrand blocks dividing said plates and interposed pluralityof pairs of.spaeed and oppositely granular material into a'pluralityo'fsymmetrical groups, and a plurality of refractory terminal members, ofwedge shape, movable. in a dire tion at right angles to the plane ofsaid circular path for operatively engaging said pairs of end blocks andfor compressing said granular material and plates.

7. In an electric resistance furnace, in combination. a plurality ofradially extending, relatively thin, ltat refractory resistor plateslocated in spaced relation in asubstantially circular path, granularell-(triccouduetiug material hetweeu said plates, a plurality of pairsof spaced amtop positely beveled refractory cud blocks dividing saidplates and interposcrl granular material into a plurality of s\-'|umetrical groups, a pluralitynf refractory terminal uu-uihers,ofwedge end blocks. and resilient means for moving Silltl terminal membersin a direction at right angles to the. plane ot said circular path toclosely engage said end hlucks and granular material between ORA A.001.1; 12

